Hi Felix!
> I'd like to (re)propose Dave's patch from the last October to
> address the problem of atime never making to the disk. Many
> people complained about it.
Tested here on 2.6.30 & works perfectly. I noticed that "strictatime" and
"relatime" mounts options can't be used with XFS - had to change the default
directly in fs/namespace.c.
> Can you run some benchmarks to see what impact it has with the
> new relatime default?
I did some benchmarks here and wasn't able to see any significant differences,
even when atime is fully enabled. The tests were done with kernel 2.6.30 on a
VMWare ESXi Server 3.5.0. Real Hardware is a dual Quad Xeon 2.66GHz, 6-disk
146GB 15k RAID5 on PERC6 with 128MB BBU cache.
xfs_info of test fs
--------------------
meta-data=/dev/sda3 isize=256 agcount=4, agsize=2365440 blks
= sectsz=512 attr=2
data = bsize=4096 blocks=9461760, imaxpct=25
= sunit=0 swidth=0 blks
naming =version 2 bsize=4096 ascii-ci=0
log =internal bsize=4096 blocks=32768, version=2
= sectsz=512 sunit=0 blks, lazy-count=1
realtime =none extsz=4096 blocks=0, rtextents=0
bonnie++ results
----------------
bonnie_relatime_nopatch.txt
Version 1.93c ------Sequential Output------ --Sequential Input- --Random-
Concurrency 1 -Per Chr- --Block-- -Rewrite- -Per Chr- --Block-- --Seeks--
Machine Size K/sec %CP K/sec %CP K/sec %CP K/sec %CP K/sec %CP /sec %CP
gentoo-x64-xfste 2G 1261 97 191145 34 95765 27 2951 97 234814 22 1169
17
Latency 12375us 271ms 927ms 11581us 17640us 54677us
Version 1.93c ------Sequential Create------ --------Random Create--------
gentoo-x64-xfstest -Create-- --Read--- -Delete-- -Create-- --Read--- -Delete--
files:max:min /sec %CP /sec %CP /sec %CP /sec %CP /sec %CP /sec %CP
32:100000:10/64 3951 42 1842 26 15114 87 4240 44 170 2 7004 57
Latency 622ms 19046us 156ms 543ms 106ms 1080ms
1.93c,1.93c,gentoo-x64-xfstest,1,1246251173,2G,,1261,97,191145,34,95765,27,2951,97,234814,22,1169,17,32,100000,10,,64,3951,42,1842,26,15114,87,4240,44,170,2,7004,57,12375us,271ms,927ms,11581us,17640us,54677us,622ms,19046us,156ms,543ms,106ms,1080ms
bonnie_relatime_withpach.txt
Version 1.93c ------Sequential Output------ --Sequential Input- --Random-
Concurrency 1 -Per Chr- --Block-- -Rewrite- -Per Chr- --Block-- --Seeks--
Machine Size K/sec %CP K/sec %CP K/sec %CP K/sec %CP K/sec %CP /sec %CP
gentoo-x64-xfste 2G 1271 99 284571 57 120562 27 2925 98 234804 24 1227
19
Latency 12436us 429ms 145ms 13323us 11892us 48055us
Version 1.93c ------Sequential Create------ --------Random Create--------
gentoo-x64-xfstest -Create-- --Read--- -Delete-- -Create-- --Read--- -Delete--
files:max:min /sec %CP /sec %CP /sec %CP /sec %CP /sec %CP /sec %CP
32:100000:10/64 3178 46 2308 32 17881 96 4451 54 171 2 7380 60
Latency 573ms 17378us 28025us 77271us 326ms 928ms
1.93c,1.93c,gentoo-x64-xfstest,1,1245948051,2G,,1271,99,284571,57,120562,27,2925,98,234804,24,1227,19,32,100000,10,,64,3178,46,2308,32,17881,96,4451,54,171,2,7380,60,12436us,429ms,145ms,13323us,11892us,48055us,573ms,17378us,28025us,77271us,326ms,928ms
bonnie_atime_withpatch.txt
Version 1.93c ------Sequential Output------ --Sequential Input- --Random-
Concurrency 1 -Per Chr- --Block-- -Rewrite- -Per Chr- --Block-- --Seeks--
Machine Size K/sec %CP K/sec %CP K/sec %CP K/sec %CP K/sec %CP /sec %CP
gentoo-x64-xfste 2G 1309 99 166258 21 117374 29 3015 98 223034 25 1182
22
Latency 8626us 496ms 23729us 9696us 28558us 43342us
Version 1.93c ------Sequential Create------ --------Random Create--------
gentoo-x64-xfstest -Create-- --Read--- -Delete-- -Create-- --Read--- -Delete--
files:max:min /sec %CP /sec %CP /sec %CP /sec %CP /sec %CP /sec %CP
32:100000:10/64 3696 52 1806 27 16913 89 4072 60 167 2 6838 58
Latency 600ms 21008us 26798us 55639us 1068ms 1045ms
1.93c,1.93c,gentoo-x64-xfstest,1,1245923465,2G,,1309,99,166258,21,117374,29,3015,98,223034,25,1182,22,32,100000,10,,64,3696,52,1806,27,16913,89,4072,60,167,2,6838,58,8626us,496ms,23729us,9696us,28558us,43342us,600ms,21008us,26798us,55639us,1068ms,1045ms
bonnie_noatime.txt
Version 1.93c ------Sequential Output------ --Sequential Input- --Random-
Concurrency 1 -Per Chr- --Block-- -Rewrite- -Per Chr- --Block-- --Seeks--
Machine Size K/sec %CP K/sec %CP K/sec %CP K/sec %CP K/sec %CP /sec %CP
gentoo-x64-xfste 2G 1302 99 312421 52 115066 29 3121 99 243930 24 1282
18
Latency 7750us 562ms 24417us 10083us 12990us 50122us
Version 1.93c ------Sequential Create------ --------Random Create--------
gentoo-x64-xfstest -Create-- --Read--- -Delete-- -Create-- --Read--- -Delete--
files:max:min /sec %CP /sec %CP /sec %CP /sec %CP /sec %CP /sec %CP
32:100000:10/64 3917 55 1942 28 16849 91 4043 59 172 2 7705 63
Latency 312ms 105ms 3530us 130ms 159ms 690ms
1.93c,1.93c,gentoo-x64-xfstest,1,1245922347,2G,,1302,99,312421,52,115066,29,3121,99,243930,24,1282,18,32,100000,10,,64,3917,55,1942,28,16849,91,4043,59,172,2,7705,63,7750us,562ms,24417us,10083us,12990us,50122us,312ms,105ms,3530us,130ms,159ms,690ms
hth,
Michael
|